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Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells.

Publication ,  Journal Article
Bouché, M; Zappelli, F; Polimeni, M; Adamo, S; Wetsel, WC; Senni, MI; Molinaro, M
Published in: Cell Growth Differ
July 1995

Human rhabdomyosarcoma RD cells express the myogenic regulatory factors MyoD and myogenin but differentiate spontaneously very poorly. Prolonged treatment of RD cells with the protein kinase C (PKC) activator 12-O-tetradecanoylphorbol-13-acetate (TPA) induces growth arrest and myogenic differentiation as shown by the accumulation of alpha-actin and myosin light and heavy chains, without affecting the expression of MyoD and myogenin. In this study, we show that short-term phorbol ester treatment of the cultures is sufficient to trigger myogenic differentiation but not growth arrest. Furthermore, PKC inhibitors, such as staurosporine or calphostin C, prevent TPA-induced differentiation but not cell growth arrest. These data suggest that the two events are mediated by different pathways; a possible interpretation is that the activation of one or more PKC isoforms mediates the induction of differentiation, whereas the down-regulation of the same or different isoforms mediates the growth arrest. To address the mechanism whereby TPA affects cell growth and differentiation in RD cells, we first analyzed PKC isoenzyme distribution. We found that RD cells express the alpha, beta 1, gamma, and sigma PKC isoenzymes. Only the alpha isoform is exclusively found in the soluble fraction, but it translocates to the membrane fraction within 5 min of TPA treatment and is completely down-regulated after 6 h. The other isoenzymes are found associated to both the soluble and the particulate fractions and are down-regulated after long-term TPA treatment. By immunofluorescence analysis, we show that the PKC alpha down-regulation is specific for those cells that respond to TPA by activating the muscle phenotype. We propose that TPA-induced differentiation in RD cells is mediated by the transient activation of PKC alpha, which activates some of the intracellular events that are necessary for MyoD and myogenin transacting activity and for the induction of terminal differentiation of RD cells. By contrast, the constitutively active beta 1 and sigma are responsible for the maintenance of cell growth, and their down-regulation is responsible for long-term TPA-induced cell growth arrest.

Duke Scholars

Published In

Cell Growth Differ

ISSN

1044-9523

Publication Date

July 1995

Volume

6

Issue

7

Start / End Page

845 / 852

Location

United States

Related Subject Headings

  • Tumor Cells, Cultured
  • Time Factors
  • Tetradecanoylphorbol Acetate
  • Rhabdomyosarcoma
  • Protein Kinase C-alpha
  • Protein Kinase C
  • Oncology & Carcinogenesis
  • Molecular Sequence Data
  • Isoenzymes
  • Immunohistochemistry
 

Citation

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ICMJE
MLA
NLM
Bouché, M., Zappelli, F., Polimeni, M., Adamo, S., Wetsel, W. C., Senni, M. I., & Molinaro, M. (1995). Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells. Cell Growth Differ, 6(7), 845–852.
Bouché, M., F. Zappelli, M. Polimeni, S. Adamo, W. C. Wetsel, M. I. Senni, and M. Molinaro. “Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells.Cell Growth Differ 6, no. 7 (July 1995): 845–52.
Bouché M, Zappelli F, Polimeni M, Adamo S, Wetsel WC, Senni MI, et al. Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells. Cell Growth Differ. 1995 Jul;6(7):845–52.
Bouché M, Zappelli F, Polimeni M, Adamo S, Wetsel WC, Senni MI, Molinaro M. Rapid activation and down-regulation of protein kinase C alpha in 12-O-Tetradecanoylphorbol-13-acetate-induced differentiation of human rhabdomyosarcoma cells. Cell Growth Differ. 1995 Jul;6(7):845–852.

Published In

Cell Growth Differ

ISSN

1044-9523

Publication Date

July 1995

Volume

6

Issue

7

Start / End Page

845 / 852

Location

United States

Related Subject Headings

  • Tumor Cells, Cultured
  • Time Factors
  • Tetradecanoylphorbol Acetate
  • Rhabdomyosarcoma
  • Protein Kinase C-alpha
  • Protein Kinase C
  • Oncology & Carcinogenesis
  • Molecular Sequence Data
  • Isoenzymes
  • Immunohistochemistry